Sump pump



Aug. 31, 1954 w. HUDSON SUMP PUMP 2 Sheets-Sheet l Filed DSC. 27. 1949NJ R. m@ mf. MM

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W. L. HUDSON Aug. 31, 1954 SUMP PUMP 2 Sheets-Sheet 2 Filed Dec. 27.1949 N VEN T 0R. 7%2 /HM LJfupso/i.

Afro :wn-XaY Patented ug. 31, 1954 UNITED STATES PATENT OFFICE SUMP PUMPWilliam L. Hudson, Fort Wayne, Ind., assignor to Tokheim Corporation, acorporation of Indiana Application December 27,

16 Claims. (Cl. 103-25) 1949, Serial N0. 135,153

movers which is substantially constant and which contin es as long asfluid is being pumped, and exert a substantially lower or 11o-loadreaction cumstances. may become air-locked, or lose hence change from aload reaction to a reduced a motor-circuit switch, which will be motorcircuit in closed p0- sition, and whichin response to a no-load currentin the motor circuit will be incapable of holding vtrical circuitemployed m the sump .-1 to 3; and Fig. 5 is a -peller le and forms, aleading together by influence of the large starting current, willimmediately move the switch to fully closed position.

For starting actuation of a pump motor, I may mechanically actuate theswitch in direct response to variations in liquid level or in fluidpressure, and in the case of a sump pump I desirably `move the switch toclosedposition in response to the `level of liquid in the'sump,preferably by a pressure responsive diaphragm.

Other advantages and objects of my invention will appear from thefollowing description, in which the invention is exemplified as appliedtoa sump pump.

The accompanying drawing illustrates my invention. In such drawing, Fig.1 is a vertical sec-- tion oi a sump pump embodying my invention; Fig. 2is a plan of the pulnp's'hwn in Fig.I 1;" Fig. 3 is a ragmental section,on a larger scale than Fig. l, showing details of the diaphragmmounting; Fig. 4 is a-wiring'diagram showing the elecpump of Figs.fragmental section showing amodication in which the control housing ismounted above the motor; and Fig. 6 shows a 'modication in which theliquid-level responsive Y device includes a float.

The sump pump shown in the drawing isof the submerged type, in whichthemotor ID is enclosed within a liquid-tight housing mounted directlyon the housing of the pump, and the whole assembly is adapted to besubmerged in the liquid to be pumped.

The main pump casing I2 houses the pump imvolute I6 and diffuser Itdirectly to a discharge nipple 20 which is internally threaded toreceive a discharge pipe 22. The impeller housing-is closed -by `asupporting base member 2d which has a central inlet-opening covered by ascreen 26. The motor Il) is Vmounted on the main pump casing l2, and itsyshaitl 28 passes througha central opening in that housing l2 andreceives directly the impeller M.

lThis direct mounting not only avoids the necessity for separatebearings in the pump,

to make more free-running the-rotating of the unit and hence to increasethe difference between no-load current and load current drawn by themotor. Where the ymotor shaft 28 passes through the pump casing l2, itis suitably sealed as by a conventional rotary seal comprising a stantionary sealing member 30 sealed to the casing I2 by a rubber ring3i,'and a rotating `sealing member 32 spring pressed fromthelimpellerfill against the stationary sealing member .30 Vand sealedto the shaft 28 by a rubber ring motor is enclosed by a sleeve 34mounted between the pump casing i2 and cover 3E and sealed thereto as byrubber rings 3l. The assembly is held bolts 38 and maybe provided withfahandle 39.

The control mechanism for the sump pump may be enclosed with the motor lor inra -separate housing connected thereto, either near the bottom ofthe assembly as shown in Figs. l to 3 or at the top of the assembly asshown in Figs.y 5 and 6, depending inpart upon the depth of liquid towhich the control is to be responsive. yIn the arrangement shown inFigs.f1 `to 3, the control housing is formed as part ofthe main pumpcasing l2, and comprises a laterally extending bellyshaped housing 12.2open at its outer end and vadapted to be closed by the diaphragmassembly described below. The electrical supply wires may be broughtdirectly'into the control housing, dep ed in v'52. -The'centerfo thediaphragm 50 is reinforced sponsive -electromagnet 6d, and such members52 is secured in 'Ihe adjusting screw 56 1s accessible `lthe motor inected to one side of the electromagnet 61B,- the connected to thesecond be grounded be 'integral with sirably through a pipe dllA sealedto the housing 42, and extending upward to above the normal liquid levelin the sump. The supply wires are desirably encased ina liquid-tightcable Mi, and the pipe lll is sealed at its upper end to the cable Hetas by means of a nut 48 and a compressible packing d8.

Preferably the starting 'hydrostatic pressure of liquid which may riseabout the pump in the sump. The pressure reelement may be a diaphragm50. As shown in Figs. 1 to 3, the diaphragm 50 is mounta sub-assembly ona protective cover plate control is responsive to with a pair of plates5d held together by a central fitting E5, and such fitting 55 isprovided with an internally threaded hole for the reception of anvadjusting screw 55 sealed to the iitting by a rubber ring 5l. Thediaphragm will of course be the adjusting deformation to actuatingposition.

Behind the diaphragm, and conveniently part oi-the same sub-assembly onthe cover plate" 52, there is a normally open switch comprising afpair osimple switch contact members switch member lil extends sulating arm toopeny position, conveniently by the action of the switch member 6 l.

A lever 55, fulcrumed on a bracket 66 carried in the same sub-assemblyon'4 thecover plate' 52, lies between the end of the arm 62 and theinner end oi the adjusting screw 5B. Inward movement oi the 'diaphragmact the adjusting screw 5% to move the llever 65 and mechanically tomove the armature 63- to carry the switch vE and l toward and to closedposition. rrhe sub-assembly mounted on thecover plate the open end cithe controlV housing'?, and conveniently sealed by means of aleaf-spring ina vertical'posiby the central bossof the 52, to avoid anyaccumulationof debris which would interfere withiits operation. 4throughthe the cover plate 52, which' is `central opening in desirably closedby a removable screen.

u Water Vrising about the pump willr have access'to the diaphragm 5Gthrough such screen and through one or more, openings adjacent thebottom edge of the central boss of the Coverplate 52. The diaphragm maybe and desirably is of considerable area so that a smallhydrostaticpressure will exert a considerable total force on it.

As shown in the wiring'diagram of Fig. 4, the electromagnet Sli and thenormally open motor control switch ii-ii are connected in series' with fyOne of the supply leads'is conother side of 'which' is connected by aJwire 6 to the switch blade E0. The other switch blade 4El is connectedby a wire l@ to one side of the motor i6, and the `opposite side o themotor is supply lead 1l. For safety, the whole pump and motor-ass'ernbly'may by a wire 'l2 shown in Fig. l. l In the modication shownin Fig'. 5, the control housing is mounted on top of the motor, and mayvthe cover 3% of the motor hous- `l, the control compartment is ing. Asin Fig.

enclosed in part by a diaphragm 50.

rear face a reinforcing plate 54', and

60-6I con- 63 of an electromagnet nested to the armature vB', is mountedclosed position by inward movement of the diaphragm and spring leg 80.In this case, the armature is shown as biased to open position by a coilspring 83.

In this modification of ordinarily involve a slowly progressive andimpositive closing of those switch points. When While the load and11o-load currentsl may vary in different motors, normally there Will bea difand hence the the sump, which will be efadjustinents are suitablyply Wires 68 and 7| are connected to a suitable source of current, thedevice is ready for automatic operation.

the armature tact of the switch members, the electromagnet 54 and themotor l@ initially closed.

sr'iiciently .exhausted :quantity of airr to enterthei impeller. i4.

-a wide margin oi safety sothat .normal ldriven pump,

agace-ecs 'will be 1 substantially.: reduced, say .'toz' aacurrent ofthe. order. of .4.5; amperes. ...Thisowillienergize `the .magnetilsufficiently torhold. the :.armaturezi .in switch-.closed position..This condition' will continue as longasi av continuous :supplyfiofliquid 'keeps .the pump'nnpellermnder load. As the pump lowers thelicuiid level, theliquidlevel responsive device' Ywill become.ineiiective .to close the switch, and the switchwill then be completelyunderthefindependent controllofthe currentresponsive magnet i3d.Vil'umping .will continue until the liquidnis .exhausted'irom the. sump,or to permit `a substantial When' the medium in theimpelleris largelyair, whether because the sump :liquid is exhausted or. tor-anyiotherreason, the load on the motor lll will substantiallyV decrease, L and 1in consequence the current drawn by the lmotor `willdecrease to ano-load current. .Assuming a quarter horsepower motor, asbeiorathe:current may decrease from the load eurent of 4.5...amperes toa noloadcurrentoic the orderof amperes. or less.

.This will be insufcientxin the electromagnetf,

to maintain the holding orceL-between the electrornagnet dfi and itsarmature.. and.` the magnet will then release that-armature, and theswitch members: that i will vbe released to Aopen position in responsetotheidrop.` in load on the pump unit. The motor will then stop. and willremain at rest until the yliquid-'level responsive device'- isagainerfectiveto actuate the switch to closed position.

The opening of the switchwill alsode-energize the magnet and thearmature vbias-.will move the armature and the switch to fully openposition, beyond any possibility of. iortuitous reclosing, and thisdennite stoppingof"` the operation will resuit from-even amornentarydropin current. This is of considerable advantage, especially in a sumppump, for it completely overcomes .the undesirable eiect frequentlyencountered with othercontrols,` with which. a period of irregularon-and-oi operation may occurr at the end of the load cycle, or with`which a balanced condition may occur to maintain the` pump in operationindefinitely. Thus, .if the impeller becomes air-locked, my controlwill'a'ct denitely and promptly to stop the motor, which eliminates alproblem that has beeniof concern with prior controls.

The controlmechanism is quite simple and inexpensiva'yet it gives acontrol action which is definite and reliably eiective. `Its startingactuation may be in direct response toa slowly changing condition Thecontrol is .and requires but. a small force. highly responsive, yet mayembody variations in operations do not impair its effectiveness. Thecontrol is useful in many and variousapplications. It is oi special usein combination with the motor of a pump, and ormsan especiallyadvantageous combination with a. sump pump. 1t will maintain a drivingmotor in continuous operation during .the continuance of .its intendedload, and will stop .themotor simultaneously with the dropping of thatload. The droppingo the load may depend on extraneous conditions and thecontrol will respond to a load decrease arising from any cause, whetherfrom the. desired cornpletion ot a load cycle,V from malfunction of afrom loss of pump. discharge pressure, from loss oi pump primefor fromvany other cause.

rclaim as' myv invention:

1. A sumppump; comprising: an` electric motor, apumpfimpeller .mountedonthe` shaftf'oi said rnotorf-a pump casing, closed motory and controlhousings, adiaphragm adapted tobe deflected by liquid .surrounding'thecontrol housing, a norfinally open-motor .control :switch arranged to beclosed.- in response to deection of said diaphragm, an electromagnet-ior holding saidy switch .iirclosedpositiom saidrnotor and switch andmagnet being electrically connected in series, saidfelectromagnet beingeiectivezto hold said switch closed when energized by current drawn bysaid motor under load and ineffective to hold said switch closed whenenergized by current drawnby saidrmotor under no load.

2. A- sump pump,scomprising a pump-and an Velectric motor, submersible.control housing, "a 4diaphragm adapted jto be .deiiectedby 'liquid`surrounding said control housing, a normallyl open motor-control switcharranged to be closed in response tofdeiiection of said diaphragm, andmeans responsiveto motor-circuit current to Ymaintain said switch inclosed position while said motor vis operatingunder load and to opensaid switch in response to a 'decrease in motor circuit current.

43. A: sump-pump, comprising an impeller and a casing therefor, a pumpmotor direct-connected toi said impeller, liquid-tight enclosure meansfor said :motor and providing a control-receiving space, avliduiri-level responsive device operating through a'wall oiVsaidcontrol space, a normallyopen'motor-contrclled switch in saidcontrol space and arranged vto be actuated by said liquidlevelkresponsive device, 'and means responsive tofmotor-circuit current :tomaintain said switch in closed position while said motor is operatingunder load-and `to open said switch in response to afdecrease iny motor.circuit current.

--4.f-Ai sump pump, comprising an irnpeller and .a casing therefor,a'-m0tory connected tosaid impeller, `a .liquid-tight enclosureprovidinga control-receiving space, said' control-receiving space `being enclosed`in partbyfadiaphragm responsive to hydrostaticopressure, .an adjustablemember. carried by said diaphragm, anormally open motor controlV switchinY said. control` yspace .and arranged tobe actuatedby-.said-adjustable member upon deiiection of. saiddiaphragmfand meansresponsive to motor-circuit current to maintain saidV switch in closedposition while said motoris. operatingunder loadand to open said .switchin response to a decrease-inmotor circuit current.

.5. In ccrnbinationfwitha pump, amotor drivingly connected to the pumpand drawing sub- -stantiallymore than'a certain current when driv- -ingthe pump under load and drawing substantially .less than said-certaincurrent when operating thepumprdrmarnotor circuitincluding a motorcontrol switch, anA electro-magnetic switch-hold- .ing device responsiveto'rnotor current, said electro-magnetic device exerting a f switchuholding iorcewhen the motor current is greater than said certain currentand exerting less than a switch holdingdorce when-.said motor current isless than .said certain current.

6. In av sump .pump `having a drivingA motor, a normally openmotorcircuit, means responsive to sump liquid level to. closesaid motorcircuit, and means responsive to: motor current to con- .trol said motorcircuit. after the .liquid level has been lowered by said pump.sufficiently to render said liquid-level responsive means ineffective to.maintain said. circuit closed.

motor circuit, and means to maintain said circuit v,closed andresponsive to a drop in motor current to open said motor circuit.

9. In a sump pump unit comprising a pump and a driving motor, a motormotor-control switch, a

pump unit is operating to open said circuit in response to thereon.

a drop in load tain said circuit closed, means being responsive to loadreaction on said in load on said pump unit.

13. In a sump pump unit comprising a pump and a drivingT motor, ahydrostatic-pressure responsive diaphragm, a motor-control switchenergized by rio-load current of said motor.

14. Control mecnanism for an electric-motor driven pump,

a circuit closing force in response to no-load current of said currentwhen operating under1 normal load, and drawing a substantially motorcurrent, said electromagnet a strong switch-closing force 1n response tostarting load current, to exert rent, and to exert less than aswitch-holding force in response to response to load current and toexert less than a switch-holding force in response to Ilo-load currentof said motor.

References Cited in Ithe file of this patent UNITED STATES PATENTS NameFoote Dec. 31, 1918 Skidmore, Jr. Jan. 3, 1928 Durdin, Jr Jan. 8, 1929Grith Jan. 21, 1930 Seiger Dec. 9, 1930 Regester Nov. 26, 1940 Hood June24, 1941 Goodman July 29, 1947 Number Date

